What is ZigBee home automation, how does it work, and integrate with C-Bus?
ZigBee home automation
uses the ZigBee wireless device specification, which is poised to become the global
standard for wireless control/sensor networks in residential, industrial, and commercial
applications. ZigBee home automation may also be integrated with C-Bus home automation
as described below.
|What is ZigBee home automation?
- ZigBee home automation is a home automation
system that uses wireless components that communicate
with each other using the ZigBee specifications.
- Like any wireless home automation system, ZigBee may be
easily retro-fitted into existing homes without installing additional cabling.
- Unlike other wireless home automation systems, the ZigBee specifications
that it employs have been more rigorously engineered to better suit the requirements of wireless
home automation communications, which include:
- The ability to deal with internal walls and obsticles.
- An innovative, self-configuring, self-healing system of redundant mesh-network nodes.
- Low low latency communications at low data rates (less than 250kbps).
- Low power consumption, dramatically less than WiFi or Bluetooth.
- Low equipment cost per ZigBee network node component.
- Low maintenance and low installation costs.
- ZigBee is a set of specifications created specifically for 2.4GHz wireless control and sensor
networks by the ZigBee Alliance from the IEEE 802.15.4 standard for wireless personal area networks (WPANs).
- The ZigBee Alliance formed in 2002 brings together public and private industry leaders
seeking to develop a single standard for the interoperability of proprietary wireless sensors and control
systems with each other, and with and newer technologies.
- Since the ZigBee specification was released in 2006, it has been further developed and is
now poised to become the global control/sensor network standard for a wide and varied range of
residential, industrial, and commercial applications, including home automation.
- The ZigBee standard enables wireless two-way communications over up to 20m inside a home
for control signals. As with any wireless system, range is affected by the type of walls, solid objects,
and other sources of EMI.
- ZigBee uses 2.4GHz frequencies like home WiFi, and for the same good reasons. However, the different way in
which ZigBee uses these frequencies allows a ZigBee network to co-exist with WiFi networks. Simple strategies like maintaining
at least 2m between WiFi and ZigBee devices, and at least 30MHz between the channels used by each, help further
mimimise the potential of either system to interfere with the other.
- Residential and commercial applications of ZigBee include home automation, lighting controls, smoke
and CO2 detectors, HVAC controls, home security, automatic utility meter readings, and remote control to
and digital set-top box communications. As mobile telephone operators integrate ZigBee
into smart phones and PDAs, you may use these as a remote control device. Inndustrial examples
include monitoring medical equipment, building and industrial automation, and environmental controls.
- Schneider Electric is one of the leading ZigBee Alliance members
that is further exploiting ZigBee’s potential for industrial and home automation applications,
and have produced this helpful explanation of ZigBee.
|How does ZigBee home automation work?
- ZigBee home automation networks support two types of devices:
1. Full Function Devices (FFDs) - either network coordinators, or routers
that mediate information between devices.
2. Low cost Reduced Function endpoint Devices (RFDs) that simply interact with the physical world
and communicate with their parent ZigBee FFDs.
- Every ZigBee home automation network must have a coordinator that:
- Sets up the network, is aware of all of the ZigBee nodes in that network.
- Handles and stores information.
- Acts as a repository for security keys.
- Manages the information transmitted and received within the ZigBee network.
- ZigBee supports reliable mesh, energy-efficient star, or cluster network configurations of nodes.
- Multiple ZigBee networks may co-exist in the same area.
- In a ZigBee mesh network each wireless node communicates with the one adjacent to it.
Two ZigBee nodes that cannot see each other may communicate via the mesh network of
other ZigBee nodes. If a ZigBee node fails, information may be automatically rerouted
to maintain communication between nodes.
- ZigBee devices are either awake or asleep, and they may be extremely energy efficient
by waking up only to transmit and receive.
- ZigBee supports two modes of operation capable of seamlessly managing
periodic, intermittent, or repetitive low latency data transmissions:
1. The beacon mode minimises energy consumption (ideal when using battery-powered coordinators),
by periodically waking to send beacons to the ZigBee routers to wake up other nodes
and check for incoming messages. If there are none, the nodes and coordinators go back to sleep.
2. Non-beacon mode suits ZigBee networks using mains-powered coordinators in which some
ZigBee nodes are always active and others sleep. The coordinator and routers’ receivers
never sleep continuosly listening for messages from any active node. Non-beacon mode
still uses little energy because most of the network devices can remain inactive over long
- All ZigBee devices have 64-bit IEEE addresses, though short 16-bit addresses may
be allocated to reduce packet size.
- ZigBee was engineered to use inexpensive hardware by:
- Using principally digital RF circuitry and direct sequence CDMA that requires simple low-cost analog circuitry.
- Extensively using relatively simple RFDs that are cheap to manufacture and maintain.
- Implementing the ZigBee application layer in such a way as to allow networks to grow physically without the need for more powerful power
transmitters, even when networks have very large numbers of nodes with low latency requirements.
- Simplicity - using four times fewer layers in ZigBee’s protocol stack than in Bluetooth’s for example.
- ZigBee 3.0 is the unification of the ZigBee Alliance’s market-leading wireless
standards into a single standard.
|Can wired C-Bus and
wireless ZigBee home automation be integrated together?
- Yes, when the below new hardware becomes available.
- The new Clipsal C-Bus Wiser Home Controller 2
may support connection to both a C-Bus wired home automation network,
and also to a wireless ZigBee home automation network, when the required optional ZigBee interface
units are released in Australia.
- A Clipsal ZigBee Interface Unit of one of the below two types needs to used with the Clipsal C-Bus Wiser Home Controller 2:
1. The Clipsal 5200UZI USB ZigBee Interface Unit, which may be installed neatly inside a
Wiser 2 Home Controller; or
2. The Clipsal 5200EZI Ethernet ZigBee Interface Unit, which may communicate with
your Wiser 2 over your LAN.
- The Clipsal ZigBee Interface Units may connect to an existing ZigBee network using Easy (E) mode.
- Clipsal Zoolkit software on a PC connected to a Clipsal ZigBee Interface Unit may be used to:
- View and control the devices on the ZigBee network.
- Retrieve the ZigBee network configuration and create a file that may be used by PICED software
to create and upload a home automation project file to the Wiser Home Controller 2.
- Integration of Clipsal C-Bus home automation and ZigBee home automation devices
should be performed by a qualified and experienced home automation Systems Integrator
such as a Clever Home automation